This invention relates to fuel controls for gas turbine engines and more particularly to computational devices for producing output signals reflecting a scheduled fuel flow for particular engine operating conditions.
The proper scheduling of acceleration and deceleration fuel flow to the burners of a gas turbine engine typically requires utilization of a number of engine parameters such as compressor inlet temperature, engine speed and compressor discharge pressure. Compressor discharge pressure is indicative of the engine air flow which must be determined so that the proper fuel-to-air ratio in the engine burners will be established. Failure to achieve the currect fuel-to-air ratio can result in compressor stall or overtemperature conditions.
Most conventional fuel controls for gas turbine engines employ pressure sensors to directly measure the compressor discharge pressure. Such sensors usually are adapted to produce either an electrical or mechanical output signal. Obviously, any malfunctioning or complete failure of the compressor discharge pressure sensor will vitiate the capability of the fuel control to accurately schedule fuel flow.